Project Abstract Preventive care for adolescents is vitally important for maximizing their health and well-being[1]. Unfortunately, pediatric primary care frequently fails to meet the preventive needs of adolescents as demonstrated by poor health outcomes for this population [2]. In this grant application, we propose to expand an existing CDSS into our adolescent primary care practices for the purpose of implementing a comprehensive, and developmentally appropriate, screening and physician decision support process. Prior work completed by our research group has demonstrated the feasibility of using CDSS to implement and evaluate clinical guidelines [5, 6]. We seek to positively impact the effectiveness of preventative primary care visits by applying this previous success to our adolescent practice. We hypothesize that the implementation of developmentally appropriate universal screening practices, using tablet technology, and enhanced physician decision support regarding clinically relevant guidelines for all annual adolescent preventive care visits will result in better health outcomes, including higher rates of adherence to physician recommendations and improved patient functioning. The specific research aims of this proposal are: Aim 1: Expand and modify an existing CDSS to include an Adolescent Preventive Care Module comprised of developmentally appropriate screening tools for adolescents aged 11 to 21 years and tailored evidence-based clinical decision support for physicians. Aim 2: Evaluate the impact of the Adolescent Preventive Care Module on the identification of specific mental and physical health problems and treatment outcomes in an adolescent primary health care setting. Adolescent primary care issues of interest for this project include sexually transmitted infection (STI), depression, substance use and Human Papillomavirus (HPV) immunization. We expect this project to improve the health outcomes of adolescents, guide future efforts to implement universal screening and CDSS in a variety of primary care settings, and provide additional evidence to support broad-based electronic screening and computerized decision support for use in preventive care as a method for improving adolescent health. Keywords: Adolescent; Screening; Primary Care; Computer Decision Support Systems